Operating mechanism for vehicle dumping bodies



May 23, 1939.

' H, A. cEDERsTRoM OPERATING MECHANISM FQR "EHICLE DUNPING BODIES Original Filed July 10,' 1933 5 Sheets-Sheet l oooo 0 MOMO.

m s m ry. T S N NRW." m NE MT AVA A. DM L om; QT Smm? INVENTOR ofzRsTHoM 5 Sheets-Sheet 2 *M mm. non. vo

H. A. CEDERSTROM ATTORNEYS Original Filed July 10, 1933 OPERATING MECHANISM FOR VEHICLE IJUMPING BODIES 'May 23, 1939.

May 23, 1939.` ||A A. cEDERs-rRoM OFERATING MECHANISMFOR VEHICLE DUMPING BODIES original Filed July 1o, 193s 5 sheets-sheet 3 Q E HAnoLDACEDaRs-rnom W :3 BY M, @LA ufr-LM ATTORNEYS May 23, 1939- H4 A. cEDERTRoM 2,159,470

OPERATING MECHANISM FOR VEHICLE DUMPNG BODIES Original Filed July 10, 1933 5 Sheets-Sheet 4 BY f2.4 WM

ATTORNEYS May 2,3, 1939. H. A. cl-:DERSTROM 2,159,470

OFERATING MECHANISM FOR VEHICLE DUMPING BODIES Original Filed July l0, 1933 5 Sheets-Sheet 5 ma/f INVENTOR 15s l0 HAROLD A. CEDERSTROM ATTORNEYS i Patented May 23, 1939 UNITED STATES PATENT OFFICE OPERATING MECHANISM FOR VEHICLE' DUMPING BODIES Original application July 10, 1933, Serial No. 679,643. Divided and this application January 28, 1937, Serial No. 122,785

3 Claims.

This invention relates to vehicles or trailers provided with dumping bodies, and more particularly to an improved operating mechanism for tilting the body thereof to load-dumping position, and is a division of my Patent No. 2,072,728, issued March 2, 1937..

The present invention concerns itself more particularly with the construction of the body dumping mechanism and has as an object, to provide such a mechanism which is supported entirely upon the vehicle supporting the tiltable body and which is comparatively light in weight, is simple and inexpensive in construction, and is positive and eiiicient in operation, whereby the apparatus may be operated at a comparatively low operating and maintenance cost.

A further object of the invention is to provide a semi-trailer adapted to `be connected to a truck and having a body mounted thereon adapted to be tilted, and a body tilting mechanism being mounted directly upon the frame of the trailer, and which mechanism derives its power from the power take-off shaft of the truck engine.

A further object is toprovide an apparatus of the class described comprising a semi-trailer having a frame provided with a rear axle and suitable load-carrying wheels, and a body mounted thereon for tilting movement and having an operating mechanism supported directly upon the frame of the trailer, said mechanism comprising means for equalizing the power required to tilt the body from its normal horizontal position to an inclined load-dumping position, whereby the mechanism is relieved of severe strains and stresses.

A further object is to provide a vehicle having a body mounted thereon for tilting movement and comprising a mechanism for tilting said body which is operated by a hydraulic hoist supported upon the frame of the vehicle, said hoist being provided with a safety device for rendering it inoperative when the body reaches the limit of its upward movement to thereby avoid damage to the mechanism, should the operator inadvertently fail to stop the hoist.

A further object is to provide a semi-trailer comprising a frame having its rear end portions supported upon suitable load-carrying wheels and having its forward portion provided with a ith wheel member adapted to be coupled to a complementa] fifth wheel member provided upon the rear end of a motor truck or tractor, and said trailer having a load-carrying body mounted thereon for tilting movement, and also having a mechanism supported directly upon the trailerV for tilting said body to load dumping position, and a hydraulic hoist being carried upon the trailer frame and having a pump adapted to circulate iiuid therethrough to tilt the body, said pump being driven from the truck engine through a 5 series of shafts and bevel gears incorporated in the construction of the fifth wheel, and a control valve being provided in connection with a hoist for controlling the circulation of fluid therethrough, and means being provided adjacent the 10 drivers seat on the truck for manipulating said control valve, and whereby said valve may be conveniently operated, regardless of the relative position of the trailer with respect to the tractor.

Other objects of the invention reside in the novel construction of the parts constituting the lifting mechanism of the load-carrying body; in the specic construction of the valve mechanism for controlling the circulation of the uid through the hoist; in the operating means for said valve mechanism, whereby the latter may be operated from the drivers seat on the truck, regardless of the angular position of the truck with respect to the trailer, and whereby the movement of the dumping body may be controlled at will so that 25 its contents may be gradually discharged therefrom, if desired; and, in the unique arrangement of the various parts of the body dumping mechanism, whereby they may readily be embodied in the construction of the semi-trailer. 30

Other objects of the invention will appear from the following description and accompanying drawings and will be pointed out in the annexed claims.

In the accompanying drawings, there has been 35 disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is not conned to the exact features shown as various changes may be made within the scope of the claims which y follow.

In the drawings:

Figure 1 is a side elevation, partially in section, illustrating the mechanism for tilting the load carrying body to a load dumping position;

Figure 2 is a plan view of Figure l;

Figure 3 is an enlarged sectional plan view on the line 3 3 of Figure 4, to more clearly illustrate the hydraulic hoist; 50

Figure 4 is a sectional elevation on the line 4--4 of Figure 3;

Figure 5 is an enlarged detail sectional view on the line 5 5 of Figure 4, showing the construction of the main control valve: 55

Figure 6 is a detail sectional View on the line 6-6 of Figure 5;

Figure 7 is a fragmentary view, showing the fifth wheel and the means for actuating the push rod of the main control valve;

Figure 8 is an enlarged detail sectional view, showing the arrangement of the control levers at the front end of the trailer frame;

Figure 9 is a vertical sectional view on ther line 9-9 of Figure 2, showing the means for transmitting power from the truck engine to the vehicle dumping mechanism; Y

Figure 10 is a diagrammatic View illustrating the change in leverage of the lifting mechanism, whereby the power required to lift the loadcarrying body from horizontal to load-dumping position is substantially equalized during the entire operation of tilting the vehicle body; and

Figure 11 is a diagrammatic view showing the trailer coupled to a truck, and also showing the driving connection between the power take-off shaft of the truck and the operating mechanism of the trailer.

Truck In the selected embodiment of the invention here shown, there is illustrated in Figure 4, for purposes of disclosure, a commercial type oi truck comprising the usual chassis 2, front and rear wheels 3 and 4, respectively, cab 5, and engine 6. The engine is shown provided with the usual power take-off shaft I0. The trailer is coupled to the tractor by a suitab-le fifth wheel structurecomprising a lower member 1', pivotally supportedY upon the chassis 2 by suitable means, not shown. A pair of coupling dogs 8 are shown mountedupon the member 1, and are adapted to be retained in operative position by a locking bar 9, slidably mounted in suitable guides provided in the fifth wheel member 1. Suitable springs I`I connecting the locking bar 9 to the dogs 8, whereby said springs constantly urge the locking bar 9 in a direction to engage the dogs 8. The springs also act to support the dogs in inoperative positions, when the locking bar is moved out of locking engagement therewith. The fifth wheel member 'I is shown provided with rearwardly and downwardly extending arms I2, spaced apart as shown in Figure 7, to provide a gap therebetween adapted to receive a king pin I3 mounted on the trailer.

Trailer An important feature of this invention resides in the construction of the semi-trailer and its operating mechanism. As shown in Figures 1 and 1-1, the trailer comprises a dumping body Illihaving a suitable supporting frame, generally indicated by the numeral I5, and composed of longitudinally extending side members I6 and transversemembers IT, securedv to the side members I6, and upon which the dumping body I4 is directly supported, as clearly illustrated in Figure- 1.

The dumping body I4 is shownv pivotally supported upon a main supporting frame, generally indicated bythe numeral I8, by a suitable cross shaft I'B mounted in suitable bearings provided at the rear end.v of the frame I8. The frame I8 constitutes the main supporting frame of the tra-iler,.`and' comprises side members 2| secured together in spaced relation by suitable cross mem-- bers.- 22, 2.3,and' 241. u'I'herear end portion of the`r trailer'fr'ame I 8: is resiliently supported upon suitable semi-elliptic` springs 25, secured` to anv axle 26 provided with suitable carrying wheels 2'I. The rear ends of the springs 25 are shown pivotally connected to a cross member 28 secured to frame members 29 interposed between the cross member 28 and the side members 2| of the main frame I8. The forward ends of the springs 25 are connected by suitable shackles 3| to a cross member 32, which also is secured to the frame members 29. The forward ends of the members 29 are shown secured to a suitable transverse channel member 33, as shown in Figure 1. The forward end of the trailer is Supported upon the ifth wheel member 1, as shown and described in detail in the application, hereinbefore mentioned.

Lifting mechanism Another feature of this invention resides in the means provided for tilting the body I4 to a load dumping position, as indicated by the dotted lines in Figure 1. Such means comprises a pair of camv members 34 mounted for oscillatory movement upon pivpts 35 secured to the side frame members 2I of the main frame, and a pair of auxiliary frame members 3.6, secured to the cross members 22 and 23 in spaced parallel relationk to the main frame members 2|. 'I'he cam members 34, it will be noted by reference to Figure 2, are supported between the frame members 2I and 36. Suitable links 31 connect the lower ends of thecam members 34 with the dumping body I4, so that when the cams are rotated, the body will be tilted from the full line position shown in Figure 1v to an inclined position.

The cams 34 are shown provided with suitable sprocket teeth 38 adapted to receive chains 39. 'Ihe end links 4I of the chains are secured to their respective cams by suitable pins 42, as shown in Figure 1. From the lower ends of the carns- 34A, the chains 39y pass upwardly over a pair of idler sprockets 43 mounted upon suitable studs 44 securedin position between the main frame members 2-I and 36. 'I'he forward ends ofthe chains are connected to the ends of an equalizer bar 45; guide slots 46 provided in the auxiliary frame members 36, as shown in Figure 1, whereby it adapted for relative movement lengthwise of theA main frame I8. The overall length of the equalizer bar 45l is slightly less than the spacing' between the side frame members 2|, whereby it may move freely therebetween, in a direction lengthwise of the trailer, while its movement in a cross-wise direction is restricted by the frame members 2I.

The cam members 34 are shaped to substantially equalize the power exerted upon the equalizer bar 45` to lift the body I4 from its normal horizontal position to its load-dumping position, shown in Figure 1. toV tilt the body, the cam members are so constructed as to cause the leverage to constantly vary during the lifting of the body, thereby to compensate for the shifting of the center of gravity of the load in a rearward direction towards the axis 35, about which the body tilts, during the operation of dumping the load. In other Words, when the cams are in their normal positions, as shown in Figure 1, they present their greatest leverage to the power mechanism, which will subsequently be described. As the body is initially moved from its horizontal position to a load-dumping position, the leverage constantly decreases in substantially direct proportion to the rearward shiftingr of the center of This equalizer bar is mounted in suitable A To thus equalize the power gravity of the load, as the load is tilted, whereby the pressure in pounds exerted against the equalizer bar by the hoist is substantially equalized.

Figure 10 clearly illustrates the effect obtained by the cam members. In this figure, it will be noted that when the cams are in their normal positions, the chains 39 will be engaged with the peripheries of the cams at their greatest diameters. In other words, the spacing between the axis of the pivots 35 and the chains 39 will be equal to the distance between a and b in Figure 10. As the cams are rotated by the action of the chains, the leverage between the axis of the pivots 35 and their respective chains 39 gradually decreases, as will be clearly noted by reference to Figure 10, wherein it will be seen that when the chains 39 are substantially at right angles to an imaginary line drawn between a and c, the leverage will be shorter than when the chains are at substantially right anglesto the line ab. In like manner, as the chains leave the peripheries of their respective cams at points d, e, and f, the leverage is progressively decreased, so that when the body I4 reaches the limit of its upward movement, indicated by the dotted lines in Figures 1, the` pressure exerted against the equalizer bar will be substantially equal to the pressure exerted thereagainst when the load is initially moved from its horizontal position. The design of the cam members and their connections with the body I4 and with the chains 39 is therefore of utmost importance.

Actual experiments have shown that a vehicle dumping body equipped with the novel cam mechanism herein disclosed, may be operated with considerably less power than when equipped with an operating mechanism of ordinary construction, whereby less power is required to 0perate such a body of a given size and load, with the result that a smaller truck motor may be used.

Means is provided for initially starting the body I4 in its return movement to normal position, should the center of gravity thereof be so disposed with respect to the axis of the pivots 35 as to prevent the body from commencing its return movement by gravity, when the fluid pressure is released therefrom, Such means is shown comprising a pair of suitable compression springs 202, one for each cam member 34, mounted upon rods 203 having their upper ends forked and pivotally connected to the cam members 34 by the pins or bolts 42. 'I'he rods 203 are slidably supported in guides 204l secured to the cross frame member 22, as best shown in Figure 1. When the dumping body I4 reaches the limit of its upward tilting movement, the springs 202 will be compressed between the nuts 205 on the lower end of the rods 203 and the guides 204. When thus compressed, the springs will act to return the cam members to their normal positions, immediately upon the release of the hoisting mechanism, subsequently to be described.

H oist n I'he hoist comprises a suitable oil tight casing 41 having a head 48 secured to one end thereof which, in turn, is suitably secured to the cross member 22 of the main frame, thereby to provide a support for the rear end of the hoist. A suitable plate 49 provides a closure for the opposite end cf the casing 41. This plate may be suitably welded to the walls of the casing to provide leak-tight connections between said parts. In Figures 2 and 3, the hoist is shown provided with two cylinders 5I which are substantially alike in construction and may be formed from suitable tubing. The rear ends of the cylinder are seated in suitable recesses 52 provided in the head 48. Suitable apertures are provided in the plate 49 at the opposite end of the hoist for receiving the forward ends of the cylinders 5I. Ihe cylinders are suitably welded to the plate 49 to secure them in place.

Pistons 53 are mounted in the cylinders 5I and are provided with piston rods 54, slidably supported at the forward end of the hoist by suitable guides 55 secured to the plate 49. The guides 55 provide closures for the forward ends of the cylinders, as clearly illustrated in Figure 3. Suitable gaskets 56 are interposed between the guides 55 and plate 49 to prevent leakage therebetween. Each guide 55 is provided with a suitable packing 51 adapted to be compressed between suitable packing glands 58 and 59, the latter being mounted for relative axial movement, and having a screw 6I for securing it in position.

A cross head 62 is secured to the forward ends of the piston rods 54 and has a forwardly eX- tending forked member 63 adapted to be connected to the equalizer bar 45 by a suitable pin 64. Thus, the pistons 53 are operatively connected to the equalizer bar 45 so that when reciprocated within their respective cylinders, the chains 39 will be operated to rotate the cam members 34 about their axes.

The means for circulating the pressure fluid within the hoist consists of a suitable pump 65 which may be of any well-known construction applicable for the purpose, and it is therefore thought unnecessary herein to show and describe the same in detail. The pump 65 has an intake 66 at its lower portion which terminates adjacent to the bottom wall of the casing 41. The outlet 61 of the pump is shown connected to a suitable ball check valve 68 which, in turn, has a pipe 69 connecting it with the plate 48 through a suitable connection 1 I, including a packing box 12 and movable gland 13, as shown in Figure 3. An orifice 14 connects the pipe 69 with a transverse uid distributing passage 15, the ends of which communicate with the rear ends of the cylinders, as clearly shown in Figure 3. By thus connecting the pump 65 with the cylinders 5I,

when the pump is operated, the fluid will be drawn from the bottom of the casing 41 into the pump, from whence it is discharged through the pipes 61 and 59 into the distributing passage 15, and thence into -the cylinders 5I, whereupon the pistons 53 will move forwardly from the position shown in Figure 3, and thereby impart a similar movement to the equalizer bar 45. Suitable relief ports 16 are provided in the walls of the cylinders 5! adjacent the forward ends thereof, whereby the fluid pumped into the cylinders will be released therefrom, when the pistons reach the predetermined positions, indicated by the dotted lines 'i'l' in Figure 3.

Valve mechanism Means is provided for releasing the fluid from the cylinders 5I .to permit the body I4 to return to its normal horizontal position, after its contents have been dumped therefrom. Such means is clearly shown in Figures 3, 4, 5, and 6, and comprises a main valve, generally indicated by the numeral 18. This valve comprises a housing 19 having a plug valve 8| rotatably mounted therein and provided with a suitable fluid circulating passage 82 adapted to be moved into regisrear end of the casing 41.

tration with alined apertures 83, provided in the valve housing, as shown in Figure 6. A pipe 84 has one end connected to the intake side of the valve and its opposite end to the plate 48 at the The pipe 84 communicates with the distributing passage 15 through an orifice 85, shown in Figure 3.

The discharge side of the valve 18 has a pipe 8B connected thereto by a suitable elbow 81. The lower end of the pipe 86 is shown connected to the lower wall of the hoist casing 41 by suitable clamping nuts 88 and 89, best shown in Figure 4. Discharge openings 9| are provided in the pipe 86 adjacent to the lower end thereof. When the plug valve 8| is positioned as shown in Figure 6, communication is established between the distributing passage 15 and the interior of the casing 41, through the valve 18, whereby the pressure iluid or oil contained in the cylinders back of the pistons, is permitted to return to the interior of the casing 41 and thus allow the body I4 to return to its normal horizontal position.

The means for operating the plug valve 8| is shown in Figures 3, 4, and 5, and comprises a ratchet 92 xedly secured to the protruding end of the plug valve 8| by a suitable washer 93 and lock screw 94. The end portionv 95 of the plug valve 8| is preferably squared as shown in Figure 5, to prevent relative rotation of the ratchet 92 thereon. The ratchet has a cylindrical hub 96 which provides a bearing for a hub 91 of an arm 98', which is retained upon the hub 96 of the ratchet by the washer 93, as will be clearly understood by reference to Figure v5.

A spring-actuated bolt 99 is mounted in the arm 98 and is adapted to engage the ratchet 92 and intermittently rotate it. Suitable means, not shown, is provided for preventing the bolt 99 from relatively rotating in its guides. Suitable gear teeth |0| are provided upon the hub 91 of the arm 98, which mesh with a rack |02 secured to a sleeve |03 having one end secured to an operating rod |04 by suitable bolts |05.` The rear end portion of the sleeve |03 is slidably engaged with a rod |06 secured to the rear wall 48 of the hoist casing 41. The spring |01 is coiled about the rod |06 and has one end seated against the rack |02 and its other end against the head 48, whereby the sleeve |03 is constantly urged in a forward direction. 'I'he forward end of the sleeve |03 abuttingly engages the rear end of a tubular guide |08, as shown at |09. The tubular guide |08 may be suitably secured to the front wa1l49 of the casing 41 by such means as welding.

Means is provided for securing the plug valve 8| of the valve 18 in its open and closed positions, as shown in Figures 5 and 6, and comprises a spring-actuated pin having a ball point ||2 adapted to engage the periphery of the plug valve 8|. Ihe ball point ||2 of the pin is situated in the plane of the uid circulating passage 82 of the valve, and is adapted to engage a pair of diametrically disposed recesses ||3 provided in the periphery of the valve 8|. 'Ihe pin III is slidably supported in a guide I4 having a cap I|5 received in threaded engagement therewith, and in which is mounted a spring IIB which constantly bears against the outer terminal of the pin II I. By relatively rotating the cap ||5 upon the guide H4, the tension of the spring may be varied. Because of the ratchet.92, the valve 8| always rotates in one direction, and approximately 90" for each oscillation ofthe arm 98,

j whereby the valve 18 will always comev to rest with the passage 82 thereofalined with the ports 83, or at right angles thereto.

To control the movement of the load-carrying body |4, when being tilted from its normal to its load-dumping position, an auxiliary valve is provided, whereby a portion of the fluid circulated by the pump- 65 is permitted to by-pass into the casing 41 in lieu of being pumped directly into the pipes 61 and 69 leading to the cylinders. This valve is best shown in Figures 3 and 4 and is generally indicated by the numeral |13. The valve |13 comprises a body |14 having an opening |15 which communicates with the pump 65, as best shown in Figure 4. A tapered seat |18 is provided in the body |14 adapted to receive a tapered plug valve 11 having a stem |18 slidably mounted in a guide in the front wall 49 of the hoist casing 41. A spring |19 is coiled about the stem |18 and has one end seated against a head |8I secured to the outer end of the stem |18, and having its opposite end seated against a packing box |82 secured to the wall 49. The spring |19 constantly urges the plug valve |11 into open position, as shown in Figure 4.

A discharge pipe |83 is connected to the pump body |14 and communicates with the passage |15 in the valve body, when the plug valve |11 is in open position. It will thus be seen that, under normal conditions, the fluid circulated by the pump 65 may by-pass through the valve |13 and back into the casing 41, particularly if the main valve 18 is closed. An adjusting screw |84 is shown mounted in one end of the valve body |14 and provides an abutment for the inner end of the plug valve |11 to prevent it from becoming wedged in its tapered seat |16.

A suitable L-shaped tting I6 Vis secured to the rear wall 48 of the hoist and communicates with the interior of the casing 41. This fitting is provided with a screw plug or closure I1 which may be conveniently removed for introduction of the pressure fluid into the casing 41. The upper portion of the L-shaped tting |I6 is coincident with the proper level of the fluid in the casing 41 so that it may be used as a guide when lling the casing. A suitable breather pipe ||8 is provided in the upper wall of the casing 41. This breather pipe has perforated caps II9 for establishing communication between the atmosphere and the interior of the casing.

To prevent the casing 41 of the hoist, and the mechanism contained therein, from becoming damaged as a result of tortional strains being imparted to the trailer frame I8, when traveling over rough, uneven ground, the forward end of the casing 41 is supported upon a single pivot 20, as best shown in Figure 4. This pivot is supported in the cross channel 33 of the trailer frame, and in a plate 30 secured to the cross member 32. A bracket 40 is suitably secured to the casing 41 and has a bore receiving the pivot 20. By thus pivotally suporting the forward end of the casing 41, and by securing the head 48 or" the casing to the cross member 22 of the trailer frame, there is provided, in effect, a three-point suspension for the hoist, whereby tortional strains imparted to the trailer frame, will not effect the operation of the movable parts thereof.

Fifth 'wheel Figure 9 illustrates the mechanism provided in the i'lfth wheel for transmitting power from the take-off shaft of the truck engine to the pump 65 of the hoisting mechanism. The fth. wheel structure is shown and described in detail in `my lil t universal joint |23 to a splined shaft |24. vopposite end of the shaft |22 is supported in a ypending application, Serial No. 679,643 and it guide bearing |25 provided in a removable plate or cap |26 having one end of a rod |21 connected thereto by a pin |28. The opposite end of the l,rod |21 is shown loosely supported between a pair of upstanding arms of a forked bracket |29, secured to the rear end portion of the frame of the truck chassis 2. A bevel gear |3| is suitably secured to the upright shaft 33 mounted in a tubular extension |34 provided on the upper wall of the gear ,casing |2|. The tubular extension |34 is rotatably supported within the king pin I3. This king pin is adapted to be engaged by the couplingr dogs 8 of the lower fifth wheel member 1, as hereinbefore described.

The king pin |3 is shown integrally formed with the plate |31 having upstanding portions |38 and |39 provided with suitable bearings for supporting a relatively short horizontal shaft 4 YThe plate |31 is suitably secured to the cross Amember 23 of the main supporting frame and to lan auxiliary cross member |42 secured to the side members 2| of the main frame. A bevel gear |43 is secured to the upper end of the upright shaft |33 and meshes with a similar gear |44 secured tothe forward end of the horizontal shaft |4|. A universal coupling |45 is secured to the rear end' of the shaft |4| and has a shaft |46 connecting it to a similar universal joint |41 secured to the shaft |48 ofthe pump 65, as clearly illustrated in Figure 2. A suitable housing |49 ber and to the upper upright portion |39 thereof vto provide a closure for the bevel gears |43 and |44. An annular member is suitably secured to the cross members 23 and 24 of the main supporting frame of the trailer and cooperates with the plate |31 to provide the upper fifth wheel member. f

The shaft |24 of the fifth wheel is operatively connected to the power take-olf shaft I9 of the truck engine, whereby said shaft may be operated from the power of said engine. To thus connect the shaft |24 to the power take-off shaft l0, a shaft |52 is connected thereto by a universal joint |53.' A splined coupling sleeve |54 is slidably engaged with the splined shaft |24, as shown in Figure 9, and has an extension |55 secured to the forward end thereof, adapted to receive the shaft section |52. The extension |55 may be secured to the splined sleeve |54 by such means as welding. The extension |55 is secured to the shaft |52 by suitable bolts |56, preferably arranged in right angular relation, as shown in Figure 9. When uncoupling the trailer from the truck, the coupling dogs 8 are released by manipulation of the locking bar 9, whereupon the truck vmay move out of engagement with the forward end of the trailer, Ait being understood that suitable means, not shown, is provided for supporting the forward end of the trailer when uncoupled from the truck. As the truck is moved away from vthe trailer, the splined coupling sleeve |54 will move out of engagement with the splined shaft extension |24, as Will readily be understood by reference to Figure 9.

To couple the trailer to the truck, the latter is moved towards the trailer until the king pin I3 is received in the gap provided between the .arms 2 of the lower fifth wheel member 1,

whereby said arms will guide the king pin into engagement with the dogs 8-8 which, by the action of the king pin, will be moved to the position shown in Figure 7, whereby the locking bar 9 will automatically move into locking engagement with the dogs by the action of the springs The rearwardly extending rod |21 of the fifth wheel operates to longitudinally aline the shaft |22 with the truck body.

Valve operating mechanism Another important feature of the invention resides in the means provided for actuating the valve 18. As shown in Figure 2, the forward end of the push rod |84 of the main valve 18 is slidably received in a guide aperture provided in the cross member 23 of the trailer frame. A suitable collar |51 is secured to said rod and is engaged by one end of a lever |58 pivoted at |59 to the cross member 23. The lever |58 is normally retained in the position shown in Figures 2 and 7 by the action of the spring |01 within the hoist, as shown in Figure 3.

The lever |58 is actuated by an arm |6| secured to one leg of a U-shaped member |62 pivotally supported upon the cross member 23 by suitable pivots |63. The U-shaped member I 62 is normally positioned as shown in Figure 8, and is adapted to be engaged by the upper edge |64 of an actuating member |65 pivoted at |66 to the lower fth wheel member 1. The actuating member |65 traverses alined elongated openings l or slots |61 and |68 provided respectively in the locking bar 9 and the horizontal wall portion of the lower fifth wheel member 1, as clearly shown in Figures 7, 8, and 9. The actuating member |65 has a depending arm |69 to which one end of a cable |1| is attached, the opposite end of which is attached to an operating lever |12 located convenient to the drivers seat within the cab of the vehicle. The U-shaped member |62 has a web |18 at its forward portion positioned to be engaged by the member |65, when the latter is actuated to oscillate the U-shaped member |62.

The means provided for operating the auxiliary valve |13 is best shown in Figures 2, 4, 7, and 8, and comprises a rod |86 having its rear end pivotally connected to one arm of a member |81 pivotally supported in a bracket |88 secured to the front wall 49 of the hoist. The opposite end of the member |81 bears against the head |8| of the valve stem |18, as clearly shown in Figures 2 and 3. The opposite end of the rod |86 passes through suitable clearance slots provided in the frame members 23 and |42, as shown in Figure 8', and is pivotally connected to one end of a bell crank |89. The bell crank |89 is shown pivotally supported upon the front frame member 24 by a suitable bracket |9|.

The means for actuating the bell c-rank 89 comprises a semi-circular member |92 having its terminals pivotally connected to the pivots |63 supporting the U-shaped member |62, as best shown in Figures '1 and 8. The semi-circular member |92 has a projection |93, alined with the lower arm |94 of the bell crank |89, so that when the member |92 is elevated from the position shown in Figure 8, the projection |93 will engage and ac-tuate the arm |94, whereupon the rod |96 will be moved forwardly to thereby depress the valve stem |16,v with the result that guide |96 and having its lower end positioned to be actuated by the leg |91 of a bell crank |98, the other leg of which has a cable |99 connecting it with an operating lever 200i, best shown in Figure 9. A projection 20| is secured to the forward portion of the semi-circular member |92 adapted to engage the lower horizontal ange of the front frame member 24, thereby to limit the downward movement kof the member |92, as will be clearly understood by reference to Figure 8.

By thus constructing the valve operating ,mechanism, the push rod |04 may be positively operated by the driver seated within the cab, regardless of the angular position of the truck with respect to the trailer. This results because the U-shaped member |62 partially surrounds the king pin 3 about whose axis the truck swings when turning corners, and because of the actuating member |65 being connected directly upon the lower fifth wheel member 1 supported on the truck. It will thus be noted that turning movement of the truck with respect to the trailer does not affect the cable |1|. When the truck is longitudinally alined with the trailer, the actuating member |65 will engage the U-shaped member |62 at its forward intermediate portion, as best shown in Figure 7, and when the truck is angularly disposed with respect to the trailer, the actuating member |65 will engage the U-shaped member at one side of its intermediate portion, as will readily be understood by reference to Figures 7 and 8.

Operation In the operation of this novel apparatus, the tilting movement of the load-carrying body |4 is controlled entirely by manipulation of the control levers |12 and 200. In Figure 11, the control levers are shown positioned direc-tly back of the cab 5 of the truck, but it is to be understood that they may be located within the cab so that they may be conveniently manipulated by the driver, whereby the entire apparatus may be conveniently operated by one man. In Figure 5, the main valve 18 is shown in closed position, wherein it will be noted that the Valve retaining bolt is seated in one end of the fluid passage 82in the plug valve 8|. When the lever |12 is manipulated, the arm 98 of the valve 'i8 will be moved from the full to the dotted line position, shown in Figure 3, causing the plug valve 8| to rotate from the position shown in Figure 5 tothat shown in Figure 6, wherein the iluid passage 82 will register with the ports 83 in the valve casing and thereby permit the flow of fluid through the valve from the pipe 84 to the pipe 86, the lower end of which communicates with the interior of the hoist casing through the apertures 9|.

The pump 65, as a result of being connected directly to the power take-off shaft of the engine, yoperates continuously when said shaft is rotated, thereby causing the fluid to circulate through the pump. The auxiliary valve |13, as hereinbefore stated, is normally in open position as shown in Figure 4, whereby the oil or fluid may circulate freely through said pump and by-.pass back into the reservoir provided within the casing 41. The fluid will circulate vthrough the auxiliary valve |13', as above described, re-

gardless of the position of the main control valve 18, assuming, of course, that the auxiliary valve is in its normal open position.

To tilt the body, the main control valve 18 is first closed by manipulation of the operating lever |12, after which the operator manipulates the control lever 200 of the auxiliary valve |13, thereby to interrupt the circulation of the iiuid through said valve. When the auxiliary valve |13 is closed, as above stated, the iiuid is forced through the pipe 61, check valve 63, pipe 69, and into the distributing passage 15 communicating with the cylinders 5|, thereby causing the pistons to be thrust forwardly by the action of the fluid being pumped into the cylinders. Such forward movement of the pistons will cause the equalizer bar 45 to move forwardly and thereby actuate the chains 39 and cause rotation of the cam members 34 on their pivots. Such action of the cam members will tilt the body |4 to an inclined loaddumping position. Should the operator inadvertently neglect to open the auxiliary valve |13, or the main valve 18, when the hoist is operating to tilt the body I4, the pressure fluid pumped into the cylinders will be automatically released therefrom, when the pistons reach the dotted line position shown in the upper portion of Figure 3, because of the pistons passing the relief ports 16, and permitting the fluid to escape from the cylinders into the reservoir within the casing 41.

The main valve 18 is either fully open or completely closed, because of the ratchet mechanism provided for actuating its plug valve 8l. The

traveling movement or speed of the load-carrying v body from normal to load-dumping position therefore, is not controlled by the main valve 18 but is controlled by manipulation of the auxiliary valve |13. When the main valve 18 is closed, and the operator closes the auxiliary valve |13, the Dump will force the fluid intoY the cylinders back of the pistons, as hereinbefore described, whereupon the body immediately begins to tilt upwardly. To retard the tilting movement of the body, the operator slightly opens the auxiliary valve |13, whereby a portion of the fluid will pass through said valve back into the reservoir, dened by the casing 41. If it is desired to completely interrupt the upward tilting movement 0f the body, the auxiliary valve is completely opened, whereby all of the fluid circulating through the pump will lay-pass through the auxiliary valve |13 and back into the reservoir, during which time the pistons will be held in fixed positions within their respective cylinders, because of the check valve 68 and closedvalve 18 preventing the fluid in the cylinders from discharging therefrom. To lower the body to its normal horizontal position, the main control valve 18 is opened.

It will thus be seen that by the provision of the control valves 18 and |13, the tilting movement of the load-carrying body |4 may be controlled at will. The auxiliary valve |13 is normally in open position, as hereinbefore stated, whereby the operator or driver must hold the control lever 200 of said valve in operative position, when dumping the load. If desired, the action of the auxiliary valve |13 may be reversed so that it is normally retained in closed position, but in actual practice, it has been found more desirable to nor- 1 mally retain said valve in open position, as above set forth.

All moving parts within theV hoist casing 41 are adequately lubricated as a result of the splashing and spraying of the oil within said casing during the operation of the hoist. In the drawings, I have shown the hoist as comprising two cylinders, but it is to be understood that in some instances, it may be desirable to use but a single cylinder, in which case, said cylinder would preferably be alined with the longitudinal centerline of the trailer so as to minimize side or lateral strains.

Because of the novel constructionand arrangement of the operating mechanism and the associated parts of the semi-trailer, the trailer may be made comparatively short, which is an important feature, in that the over-all length of the apparatus may be considerably reduced as compared to apparatus of this general nature. As hereinbefore stated, the construction of the camA members 34 and the means for operating them is of utmost importance in that it substantially equalizes the power required to lift the load from its normal horizontal position, shown in Figure 1, to the inclined load dumping position, shown in dotted lines. It is also to be noted that the load-carrying body I4 is so mounted upon the main frame of the trailer that when tilted to a load-dumping position, they center of gravity thereof will be forwardly of the rear axle 26,

whereby they trailer cannot tip over rearwardly.

' control levers |12 and 200.

The control mechanism for the dump body I4, asherein disclosed, offers the utmost in simplicity, as the raising and lowering of the dump body is controlled entirely by the manipulation of the 'I'he fth wheel is so constructed as to simplify the operation of coupling the trailer to the truck or uncoupling it therefrom. The drive shaft between the power vtake-off shaft I of the truck engine and the the return movement of the body to its normal horizontal position, and eliminate any danger of the body failing to return to its normal horizontal position when the main valve 18 is opened to'release the fluid pressure from the cylinders 5|.

I claim as my invention:

1. In a semi-trailer adapted to be connected to a truck or a tractor, a frame comprising side members connected togetherv by suitable cross members, auxiliary frame members secured to certain ofV said cross members and disposed in spaced parallel relation to said sidev members, a load-carrying bodyr pivotally mounted on said frame, cam members rotatably mounted in the spaces between said side members and said auxiliary frame members and having sprocket teeth in their peripheries, arms pivotally connecting said cam members to said body, chains operatively engaged with the teeth on said cam members and having their rear terminals suitably secured to said members, said auxiliary side members having guide slots therein, an equalizer bar slidably supported in said guide slots and connected to said chains, a hoist mounted in said frame and hav` ing a reciprocal member operatively connected to saidequalizer bar, and means for controlling the operation of the hoist whereby said cam members may be actuated to tilt the body to loaddumping position.

2. In a semi-trailer having means for connecting it to a truck or a tractor, a pair of main side members, auxiliary side members spaced inwardly from said main side members, said inner and outer side members being connected together at the front and rear by suitable cross members to provide a structural frame, a load-carrying body pivotally mounted on said frame, cam members rotatably mounted on said frame between said main and auxiliary frame members, ilexible elements secured to said cam members, an equalizer bar slidably supported in said auxiliary side frame members and prevented from longitudinal movement by the main frame members, a suitable hoisting mechanism mounted in said frame between the auxiliary frame members and having a member mounted for movement lengthwise of the frame and operatively connected to the equalizer bar, and means for controlling the operation of said hoisting mechanism, whereby the equalizer bar is operated to actuate said cam members and tilt the body to load dumping position.

3. In a semitrailer having means for connecting it to a truck or a tractor, a pair of main side members, auxiliary side members spaced inwardly from said main side members, said inner and outer side members being connected together at the front and rear by suitable cross members to provide a structural frame, a load-carrying body pivotally mounted on said frame, cam members rotatably mounted on said frame, said auxiliary frame members having horizontal slots therein, ilexible elements secured to said cam members, an equalizer bar slidably supported in said slots and having its ends disposed adjacent to said main i'rame members, aA suitable hoisting mechanism mounted in said frame between said inner frame members and having an operative connection with said equalizer bar, means for controlling the operation of said hoisting mechanism, whereby said cam members may be actuated to tilt the body to load dumping position, and links pivotally connected to said cam members and having cushion means thereon adapted to cushion the rearward tilting movement of the dumping body.

HAROLD A. CEDERSTROM. 

